Pollution drove Florida's manatees from warm springs to power plants. As the state switches to renewable energy, their new manmade homes are disappearing.
The large, grey, barnacled Florida manatees lazily float near the surface of the sheltered canal next to Apollo Beach, on the state's Gulf Coast.
The water is heated to the perfect temperature for the manatees, who can't survive in conditions below 20C (68F). The manatees' natural habitats are the warm water springs found across Florida, where the mammals spend up to eight hours a day grazing on seagrass.
But these Apollo Beach manatees – also affectionately referred to as "sea cows" – aren't feeding off the seafloor of aquamarine artesian springs, which are lined with limestone rock and surrounded by Spanish moss-draped trees. Instead, a large coal power plant looms over the creatures, pumping out warm water – an industry by-product.
An 'unbelievable' conundrum
These manatees have become dependent on the coal and gas power plants, because their historic feeding grounds, the natural springs along the Atlantic coast, have been all but destroyed through development, explains Elizabeth Fleming, a conservationist and manatee expert at the non-profit Defenders of Wildlife.
It's reaching a crisis point because as the US moves towards renewable energy, these power plants will be decommissioned and the artificial warm water source for the manatees will disappear. "It is one of the most unbelievable human-wildlife conundrums I've ever seen in my life," says Fleming. "We have totally reengineered their whole habitat."
For years, the manatees have flocked to these power plants, including the facility in Cape Canaveral, in Indian River Lagoon. But the power companies will likely phase out these warm water discharges over the next 30 years, as Florida moves towards net zero by 2050.
"We have destroyed all their springs on the Atlantic Coast," Fleming says. "We've got to figure out how to get these manatees to go to other places." A 2023 warm water Florida manatee action plan noted that "we must begin [transitioning manatees] now to avoid catastrophic losses of the Florida manatee population".
In 1997, a power plant frequented by manatees was modified to meet water quality standards – therefore eliminating its artificial warm water discharge, which is produced by using cold water to cool steam and produce electricity. The manatees, used to relying on the warm water to survive the winter months, did not leave the area, and died of cold stress.
Even though the power plants provide the warm water manatees need, it doesn't mean there's seagrass, though – which can't survive in polluted waters. Between 2011 and 2019, 47,000 acres (19,000 ha) of seagrass in the Indian River Lagoon – amounting to 58% – died off, caused by nutrient runoff and pollution. Other estimates from Save the Manatee, a non-profit group which monitors manatee populations and advocates for stronger protections, put the seagrass loss at almost 90%.
The manatees, who by now are habitually drawn to the Indian River Lagoon for the artificial warm water, wouldn't leave. And so they starved to death. During 2021 and 2022, 1,900 manatees died. "It was unprecedented," says Pat Rose, founder of Save the Manatees.
"It took a tragedy for people to understand what was happening to these manatees." So many of the animals perished that the Florida Wildlife Commission's scientists simply stopped performing necropsies, which are usually carried out every time a manatee dies.
Desperate measures
The manatee population was in crisis – and so scientists came up with a desperate plan: if there wasn't any seagrass to eat, scientists would feed them romaine lettuce. Almost 600,000lb (272,155kg) of lettuce was fed to the manatee population on Florida's east coast, mainly around Cape Canaveral, over two years in a programme named Let Them Eat Lettuce, which Rose helped oversee. It was a success, and the manatees had recovered sufficiently that they could pause the programme during the 2023 winter period.
But manatees aren't just threatened by a loss of habitat and seagrass; 96% of manatees in Florida have some kind of scars on their bodies – from boat collisions. "Virtually every manatee alive has been within an inch or two of losing its life," explains Rose. "The leading cause of their injuries and mortalities is still watercraft collisions." In Florida, manatees share the waterways with hundreds of thousands of boats. Manatees can sustain both blunt and sharp force trauma from propellers, and collisions account for almost a quarter of mortalities. And yet, motorised boats are still permitted in many of the natural springs that manatees rely on for survival.
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